66542985216 has 420 divisors, whose sum is σ = 211785596748. Its totient is φ = 20816068608.

The previous prime is 66542985211. The next prime is 66542985217. The reversal of 66542985216 is 61258924566.

66542985216 is a `hidden beast` number, since 6 + 6 + 542 + 9 + 85 + 2 + 16 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66542985211) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 191766355 + ... + 191766701.

Almost surely, 2^66542985216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66542985216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105892798374).

66542985216 is an abundant number, since it is smaller than the sum of its proper divisors (145242611532).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66542985216 is an equidigital number, since it uses as much as digits as its factorization.

66542985216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419 (or 369 counting only the distinct ones).

The product of its digits is 6220800, while the sum is 54.

The spelling of 66542985216 in words is "sixty-six billion, five hundred forty-two million, nine hundred eighty-five thousand, two hundred sixteen".